According to a leaked Apple Sales Online training manual posted on social media, Apple’s latest iPhone 12 models do not support 5G even in dual SIM mode. The PDF has been crafted for sharing with dealers and carriers.
Using multiple phone numbers is not unusual for individuals, and helps them to keep their work and personal lines apart from each other, but also use the same telephone. For those that need to have different phone numbers for some reason, using two SIM cards on a single system is simply more practical than lugging around two devices.
By means of an integrated SIM (eSIM) and a reversible SIM card slot, the new generation iPhone 12 series supports this, rather than forcing users to mount dual nano SIM cards. With the addition of one potentially very significant wrinkle, fair enough. A Reddit user posted a screenshot of a suspected paper from the websites of Apple ‘s internal distribution services that shows that 5G only operates when a single line is used.
Unfortunately, it looks like you’ll have to uninstall the second SIM slot if you want to use 5G, no matter which one you choose to use. Or so says a screenshot posted on social media pretending to be from a Sales Web tools (via MacRumours) training manual from Apple, which outlines the answer to questions about whether 5 G and dual SIM would work in tandem. But it looks like dual SIM and 5G are not going to be compatible in any situation.
This is a bit concerning, presuming that there is a limitation. The same person, however, also claims that sometime this year, Apple plans to roll out a software upgrade that will allow 5G while using dual SIM mode, so it will only be a temporary limitation (and a very short term one at that).